1. Field of the Invention:
The present invention relates to a diver flotation apparatus and more particularly to such an apparatus incorporated in the back pack of a diver.
2. Description of the Prior Art:
A SCUBA (self-contained underwater breathing apparatus) diver usually wears a back pack strapped to his person to provide a means for supporting an air tank or tanks, a weight belt about his waist to overcome his natural positive buoyancy, and a life vest inflatable to provide buoyancy compensation. Another form of back pack dispenses with the need for a weight belt by incorporating weights as an integral part of the back pack. One such type of back pack is described in my U.S. Pat. No. 3,670,509, issued June 20, 1972, and entitled "Buoyancy Adjustment Back Pack."
Although a life vest is useful to float the diver on the surface in an emergency, and is useful to a limited extent in helping the diver to reach the surface, it is primiarily useful in adjusting the buoyancy of the diver during a dive. That is, it is not always possible to accurately predict the amount of weight a diver must wear to achieve neutral or slightly positive buoyancy, so the life vest is mouth inflated underwater in an amount sufficient to establish the desired buoyancy. Undesired negative buoyancy occurs for various reasons, such as a weight gain by the diver since his last dive; too many lead weights in his belt or back pack; or compression of the foam cells in his wet suit at diving depths.
Like all equipment which the diver must wear, the life vest impairs his freedom of movement, is a bother to put on and take off, its filling tube sometimes becomes entangled in other equipment and is difficult to quickly locate, the vest is relatively expensive, and care must be exercised to keep it from becoming partially filled with water during inflation underwater. Moreover, the position of the life vest under the diver's body, across his waist and chest, provides poor hydrodynamic stability, particularly where a weight belt is used. The diver is so oriented by the locations of the various pieces of equipment that he tends to be buffeted by surface waves, particularly when swimming through surf.